Thread (14 messages) 14 messages, 2 authors, 2025-11-07

[PATCH v11 4/9] arm64: Kconfig: Detect toolchain support for LSUI

From: Yeoreum Yun <hidden>
Date: 2025-11-06 09:40:43
Also in: kvm, kvmarm, linux-kselftest, lkml
Subsystem: arm64 port (aarch64 architecture), the rest · Maintainers: Catalin Marinas, Will Deacon, Linus Torvalds

Since Armv9.6, FEAT_LSUI supplies the load/store instructions for
previleged level to access to access user memory without clearing
PSTATE.PAN bit.
It's enough to add CONFIG_AS_HAS_LSUI only because the code for LSUI uses
individual `.arch_extension` entries.

Signed-off-by: Yeoreum Yun <redacted>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/Kconfig | 5 +++++
 1 file changed, 5 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6663ffd23f25..bdbbe78160ab 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2201,6 +2201,11 @@ config ARM64_GCS
 
 endmenu # "ARMv9.4 architectural features"
 
+config AS_HAS_LSUI
+	def_bool $(as-instr,.arch_extension lsui)
+	help
+	  Supported by LLVM 20+ and binutils 2.45+.
+
 config ARM64_SVE
 	bool "ARM Scalable Vector Extension support"
 	default y
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

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